A method of the type referred to above is known from U.S. Pat. Nos. 3,880,223 and 3,965,961 (Gunnergaard). This known method is adapted for the production of foundry mold parts to be used in assembling molds for casting molten metals, such as iron and alloys thereof. The method of the present invention is also mainly intended for such use, but may be applied in the production of other articles from particulate material without exceeding the scope of the present invention, the following explanation of which being, however, based upon the foundry application referred to.
Such a method has been shown capable of producing shaped bodies of considerably improved uniformity of compactness and density throughout their extent, as compared to bodies produced using earlier methods. Practical experience has, however, shown that the resulting bodies are not yet quite perfect with regard to this uniformity, as especially narrow protruding parts, corresponding to narrow depressions in the mold chamber walls, tend to exhibit reduced compactness and density. This tendency may be ascribed to the formation of pockets of air being compressed in depressed portions of the mold chamber walls during the initial stages of the mold-filling process.